COIN-OR::LEMON - Graph Library

source: lemon-1.2/lemon/lgf_reader.h @ 503:41bdb4d6c8c3

Last change on this file since 503:41bdb4d6c8c3 was 487:afd134142111, checked in by Peter Kovacs <kpeter@…>, 11 years ago

Various fixes for compiling on AIX (#211, #212)

File size: 78.3 KB
Line 
1/* -*- mode: C++; indent-tabs-mode: nil; -*-
2 *
3 * This file is a part of LEMON, a generic C++ optimization library.
4 *
5 * Copyright (C) 2003-2008
6 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
7 * (Egervary Research Group on Combinatorial Optimization, EGRES).
8 *
9 * Permission to use, modify and distribute this software is granted
10 * provided that this copyright notice appears in all copies. For
11 * precise terms see the accompanying LICENSE file.
12 *
13 * This software is provided "AS IS" with no warranty of any kind,
14 * express or implied, and with no claim as to its suitability for any
15 * purpose.
16 *
17 */
18
19///\ingroup lemon_io
20///\file
21///\brief \ref lgf-format "LEMON Graph Format" reader.
22
23
24#ifndef LEMON_LGF_READER_H
25#define LEMON_LGF_READER_H
26
27#include <iostream>
28#include <fstream>
29#include <sstream>
30
31#include <set>
32#include <map>
33
34#include <lemon/core.h>
35
36#include <lemon/lgf_writer.h>
37
38#include <lemon/concept_check.h>
39#include <lemon/concepts/maps.h>
40
41namespace lemon {
42
43  namespace _reader_bits {
44
45    template <typename Value>
46    struct DefaultConverter {
47      Value operator()(const std::string& str) {
48        std::istringstream is(str);
49        Value value;
50        if (!(is >> value)) {
51          throw FormatError("Cannot read token");
52        }
53
54        char c;
55        if (is >> std::ws >> c) {
56          throw FormatError("Remaining characters in token");
57        }
58        return value;
59      }
60    };
61
62    template <>
63    struct DefaultConverter<std::string> {
64      std::string operator()(const std::string& str) {
65        return str;
66      }
67    };
68
69    template <typename _Item>
70    class MapStorageBase {
71    public:
72      typedef _Item Item;
73
74    public:
75      MapStorageBase() {}
76      virtual ~MapStorageBase() {}
77
78      virtual void set(const Item& item, const std::string& value) = 0;
79
80    };
81
82    template <typename _Item, typename _Map,
83              typename _Converter = DefaultConverter<typename _Map::Value> >
84    class MapStorage : public MapStorageBase<_Item> {
85    public:
86      typedef _Map Map;
87      typedef _Converter Converter;
88      typedef _Item Item;
89
90    private:
91      Map& _map;
92      Converter _converter;
93
94    public:
95      MapStorage(Map& map, const Converter& converter = Converter())
96        : _map(map), _converter(converter) {}
97      virtual ~MapStorage() {}
98
99      virtual void set(const Item& item ,const std::string& value) {
100        _map.set(item, _converter(value));
101      }
102    };
103
104    template <typename _Graph, bool _dir, typename _Map,
105              typename _Converter = DefaultConverter<typename _Map::Value> >
106    class GraphArcMapStorage : public MapStorageBase<typename _Graph::Edge> {
107    public:
108      typedef _Map Map;
109      typedef _Converter Converter;
110      typedef _Graph Graph;
111      typedef typename Graph::Edge Item;
112      static const bool dir = _dir;
113
114    private:
115      const Graph& _graph;
116      Map& _map;
117      Converter _converter;
118
119    public:
120      GraphArcMapStorage(const Graph& graph, Map& map,
121                         const Converter& converter = Converter())
122        : _graph(graph), _map(map), _converter(converter) {}
123      virtual ~GraphArcMapStorage() {}
124
125      virtual void set(const Item& item ,const std::string& value) {
126        _map.set(_graph.direct(item, dir), _converter(value));
127      }
128    };
129
130    class ValueStorageBase {
131    public:
132      ValueStorageBase() {}
133      virtual ~ValueStorageBase() {}
134
135      virtual void set(const std::string&) = 0;
136    };
137
138    template <typename _Value, typename _Converter = DefaultConverter<_Value> >
139    class ValueStorage : public ValueStorageBase {
140    public:
141      typedef _Value Value;
142      typedef _Converter Converter;
143
144    private:
145      Value& _value;
146      Converter _converter;
147
148    public:
149      ValueStorage(Value& value, const Converter& converter = Converter())
150        : _value(value), _converter(converter) {}
151
152      virtual void set(const std::string& value) {
153        _value = _converter(value);
154      }
155    };
156
157    template <typename Value>
158    struct MapLookUpConverter {
159      const std::map<std::string, Value>& _map;
160
161      MapLookUpConverter(const std::map<std::string, Value>& map)
162        : _map(map) {}
163
164      Value operator()(const std::string& str) {
165        typename std::map<std::string, Value>::const_iterator it =
166          _map.find(str);
167        if (it == _map.end()) {
168          std::ostringstream msg;
169          msg << "Item not found: " << str;
170          throw FormatError(msg.str());
171        }
172        return it->second;
173      }
174    };
175
176    template <typename Graph>
177    struct GraphArcLookUpConverter {
178      const Graph& _graph;
179      const std::map<std::string, typename Graph::Edge>& _map;
180
181      GraphArcLookUpConverter(const Graph& graph,
182                              const std::map<std::string,
183                                             typename Graph::Edge>& map)
184        : _graph(graph), _map(map) {}
185
186      typename Graph::Arc operator()(const std::string& str) {
187        if (str.empty() || (str[0] != '+' && str[0] != '-')) {
188          throw FormatError("Item must start with '+' or '-'");
189        }
190        typename std::map<std::string, typename Graph::Edge>
191          ::const_iterator it = _map.find(str.substr(1));
192        if (it == _map.end()) {
193          throw FormatError("Item not found");
194        }
195        return _graph.direct(it->second, str[0] == '+');
196      }
197    };
198
199    inline bool isWhiteSpace(char c) {
200      return c == ' ' || c == '\t' || c == '\v' ||
201        c == '\n' || c == '\r' || c == '\f';
202    }
203
204    inline bool isOct(char c) {
205      return '0' <= c && c <='7';
206    }
207
208    inline int valueOct(char c) {
209      LEMON_ASSERT(isOct(c), "The character is not octal.");
210      return c - '0';
211    }
212
213    inline bool isHex(char c) {
214      return ('0' <= c && c <= '9') ||
215        ('a' <= c && c <= 'z') ||
216        ('A' <= c && c <= 'Z');
217    }
218
219    inline int valueHex(char c) {
220      LEMON_ASSERT(isHex(c), "The character is not hexadecimal.");
221      if ('0' <= c && c <= '9') return c - '0';
222      if ('a' <= c && c <= 'z') return c - 'a' + 10;
223      return c - 'A' + 10;
224    }
225
226    inline bool isIdentifierFirstChar(char c) {
227      return ('a' <= c && c <= 'z') ||
228        ('A' <= c && c <= 'Z') || c == '_';
229    }
230
231    inline bool isIdentifierChar(char c) {
232      return isIdentifierFirstChar(c) ||
233        ('0' <= c && c <= '9');
234    }
235
236    inline char readEscape(std::istream& is) {
237      char c;
238      if (!is.get(c))
239        throw FormatError("Escape format error");
240
241      switch (c) {
242      case '\\':
243        return '\\';
244      case '\"':
245        return '\"';
246      case '\'':
247        return '\'';
248      case '\?':
249        return '\?';
250      case 'a':
251        return '\a';
252      case 'b':
253        return '\b';
254      case 'f':
255        return '\f';
256      case 'n':
257        return '\n';
258      case 'r':
259        return '\r';
260      case 't':
261        return '\t';
262      case 'v':
263        return '\v';
264      case 'x':
265        {
266          int code;
267          if (!is.get(c) || !isHex(c))
268            throw FormatError("Escape format error");
269          else if (code = valueHex(c), !is.get(c) || !isHex(c)) is.putback(c);
270          else code = code * 16 + valueHex(c);
271          return code;
272        }
273      default:
274        {
275          int code;
276          if (!isOct(c))
277            throw FormatError("Escape format error");
278          else if (code = valueOct(c), !is.get(c) || !isOct(c))
279            is.putback(c);
280          else if (code = code * 8 + valueOct(c), !is.get(c) || !isOct(c))
281            is.putback(c);
282          else code = code * 8 + valueOct(c);
283          return code;
284        }
285      }
286    }
287
288    inline std::istream& readToken(std::istream& is, std::string& str) {
289      std::ostringstream os;
290
291      char c;
292      is >> std::ws;
293
294      if (!is.get(c))
295        return is;
296
297      if (c == '\"') {
298        while (is.get(c) && c != '\"') {
299          if (c == '\\')
300            c = readEscape(is);
301          os << c;
302        }
303        if (!is)
304          throw FormatError("Quoted format error");
305      } else {
306        is.putback(c);
307        while (is.get(c) && !isWhiteSpace(c)) {
308          if (c == '\\')
309            c = readEscape(is);
310          os << c;
311        }
312        if (!is) {
313          is.clear();
314        } else {
315          is.putback(c);
316        }
317      }
318      str = os.str();
319      return is;
320    }
321
322    class Section {
323    public:
324      virtual ~Section() {}
325      virtual void process(std::istream& is, int& line_num) = 0;
326    };
327
328    template <typename Functor>
329    class LineSection : public Section {
330    private:
331
332      Functor _functor;
333
334    public:
335
336      LineSection(const Functor& functor) : _functor(functor) {}
337      virtual ~LineSection() {}
338
339      virtual void process(std::istream& is, int& line_num) {
340        char c;
341        std::string line;
342        while (is.get(c) && c != '@') {
343          if (c == '\n') {
344            ++line_num;
345          } else if (c == '#') {
346            getline(is, line);
347            ++line_num;
348          } else if (!isWhiteSpace(c)) {
349            is.putback(c);
350            getline(is, line);
351            _functor(line);
352            ++line_num;
353          }
354        }
355        if (is) is.putback(c);
356        else if (is.eof()) is.clear();
357      }
358    };
359
360    template <typename Functor>
361    class StreamSection : public Section {
362    private:
363
364      Functor _functor;
365
366    public:
367
368      StreamSection(const Functor& functor) : _functor(functor) {}
369      virtual ~StreamSection() {}
370
371      virtual void process(std::istream& is, int& line_num) {
372        _functor(is, line_num);
373        char c;
374        std::string line;
375        while (is.get(c) && c != '@') {
376          if (c == '\n') {
377            ++line_num;
378          } else if (!isWhiteSpace(c)) {
379            getline(is, line);
380            ++line_num;
381          }
382        }
383        if (is) is.putback(c);
384        else if (is.eof()) is.clear();
385      }
386    };
387
388  }
389
390  template <typename Digraph>
391  class DigraphReader;
392
393  template <typename Digraph>
394  DigraphReader<Digraph> digraphReader(Digraph& digraph,
395                                       std::istream& is = std::cin);
396  template <typename Digraph>
397  DigraphReader<Digraph> digraphReader(Digraph& digraph, const std::string& fn);
398  template <typename Digraph>
399  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char *fn);
400
401  /// \ingroup lemon_io
402  ///
403  /// \brief \ref lgf-format "LGF" reader for directed graphs
404  ///
405  /// This utility reads an \ref lgf-format "LGF" file.
406  ///
407  /// The reading method does a batch processing. The user creates a
408  /// reader object, then various reading rules can be added to the
409  /// reader, and eventually the reading is executed with the \c run()
410  /// member function. A map reading rule can be added to the reader
411  /// with the \c nodeMap() or \c arcMap() members. An optional
412  /// converter parameter can also be added as a standard functor
413  /// converting from \c std::string to the value type of the map. If it
414  /// is set, it will determine how the tokens in the file should be
415  /// converted to the value type of the map. If the functor is not set,
416  /// then a default conversion will be used. One map can be read into
417  /// multiple map objects at the same time. The \c attribute(), \c
418  /// node() and \c arc() functions are used to add attribute reading
419  /// rules.
420  ///
421  ///\code
422  /// DigraphReader<Digraph>(digraph, std::cin).
423  ///   nodeMap("coordinates", coord_map).
424  ///   arcMap("capacity", cap_map).
425  ///   node("source", src).
426  ///   node("target", trg).
427  ///   attribute("caption", caption).
428  ///   run();
429  ///\endcode
430  ///
431  /// By default the reader uses the first section in the file of the
432  /// proper type. If a section has an optional name, then it can be
433  /// selected for reading by giving an optional name parameter to the
434  /// \c nodes(), \c arcs() or \c attributes() functions.
435  ///
436  /// The \c useNodes() and \c useArcs() functions are used to tell the reader
437  /// that the nodes or arcs should not be constructed (added to the
438  /// graph) during the reading, but instead the label map of the items
439  /// are given as a parameter of these functions. An
440  /// application of these functions is multipass reading, which is
441  /// important if two \c \@arcs sections must be read from the
442  /// file. In this case the first phase would read the node set and one
443  /// of the arc sets, while the second phase would read the second arc
444  /// set into an \e ArcSet class (\c SmartArcSet or \c ListArcSet).
445  /// The previously read label node map should be passed to the \c
446  /// useNodes() functions. Another application of multipass reading when
447  /// paths are given as a node map or an arc map.
448  /// It is impossible to read this in
449  /// a single pass, because the arcs are not constructed when the node
450  /// maps are read.
451  template <typename _Digraph>
452  class DigraphReader {
453  public:
454
455    typedef _Digraph Digraph;
456    TEMPLATE_DIGRAPH_TYPEDEFS(Digraph);
457
458  private:
459
460
461    std::istream* _is;
462    bool local_is;
463    std::string _filename;
464
465    Digraph& _digraph;
466
467    std::string _nodes_caption;
468    std::string _arcs_caption;
469    std::string _attributes_caption;
470
471    typedef std::map<std::string, Node> NodeIndex;
472    NodeIndex _node_index;
473    typedef std::map<std::string, Arc> ArcIndex;
474    ArcIndex _arc_index;
475
476    typedef std::vector<std::pair<std::string,
477      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
478    NodeMaps _node_maps;
479
480    typedef std::vector<std::pair<std::string,
481      _reader_bits::MapStorageBase<Arc>*> >ArcMaps;
482    ArcMaps _arc_maps;
483
484    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
485      Attributes;
486    Attributes _attributes;
487
488    bool _use_nodes;
489    bool _use_arcs;
490
491    bool _skip_nodes;
492    bool _skip_arcs;
493
494    int line_num;
495    std::istringstream line;
496
497  public:
498
499    /// \brief Constructor
500    ///
501    /// Construct a directed graph reader, which reads from the given
502    /// input stream.
503    DigraphReader(Digraph& digraph, std::istream& is = std::cin)
504      : _is(&is), local_is(false), _digraph(digraph),
505        _use_nodes(false), _use_arcs(false),
506        _skip_nodes(false), _skip_arcs(false) {}
507
508    /// \brief Constructor
509    ///
510    /// Construct a directed graph reader, which reads from the given
511    /// file.
512    DigraphReader(Digraph& digraph, const std::string& fn)
513      : _is(new std::ifstream(fn.c_str())), local_is(true),
514        _filename(fn), _digraph(digraph),
515        _use_nodes(false), _use_arcs(false),
516        _skip_nodes(false), _skip_arcs(false) {
517      if (!(*_is)) {
518        delete _is;
519        throw IoError("Cannot open file", fn);
520      }
521    }
522
523    /// \brief Constructor
524    ///
525    /// Construct a directed graph reader, which reads from the given
526    /// file.
527    DigraphReader(Digraph& digraph, const char* fn)
528      : _is(new std::ifstream(fn)), local_is(true),
529        _filename(fn), _digraph(digraph),
530        _use_nodes(false), _use_arcs(false),
531        _skip_nodes(false), _skip_arcs(false) {
532      if (!(*_is)) {
533        delete _is;
534        throw IoError("Cannot open file", fn);
535      }
536    }
537
538    /// \brief Destructor
539    ~DigraphReader() {
540      for (typename NodeMaps::iterator it = _node_maps.begin();
541           it != _node_maps.end(); ++it) {
542        delete it->second;
543      }
544
545      for (typename ArcMaps::iterator it = _arc_maps.begin();
546           it != _arc_maps.end(); ++it) {
547        delete it->second;
548      }
549
550      for (typename Attributes::iterator it = _attributes.begin();
551           it != _attributes.end(); ++it) {
552        delete it->second;
553      }
554
555      if (local_is) {
556        delete _is;
557      }
558
559    }
560
561  private:
562
563    template <typename DGR>
564    friend DigraphReader<DGR> digraphReader(DGR& digraph, std::istream& is);
565    template <typename DGR>
566    friend DigraphReader<DGR> digraphReader(DGR& digraph,
567                                            const std::string& fn);
568    template <typename DGR>
569    friend DigraphReader<DGR> digraphReader(DGR& digraph, const char *fn);
570
571    DigraphReader(DigraphReader& other)
572      : _is(other._is), local_is(other.local_is), _digraph(other._digraph),
573        _use_nodes(other._use_nodes), _use_arcs(other._use_arcs),
574        _skip_nodes(other._skip_nodes), _skip_arcs(other._skip_arcs) {
575
576      other._is = 0;
577      other.local_is = false;
578
579      _node_index.swap(other._node_index);
580      _arc_index.swap(other._arc_index);
581
582      _node_maps.swap(other._node_maps);
583      _arc_maps.swap(other._arc_maps);
584      _attributes.swap(other._attributes);
585
586      _nodes_caption = other._nodes_caption;
587      _arcs_caption = other._arcs_caption;
588      _attributes_caption = other._attributes_caption;
589
590    }
591
592    DigraphReader& operator=(const DigraphReader&);
593
594  public:
595
596    /// \name Reading rules
597    /// @{
598
599    /// \brief Node map reading rule
600    ///
601    /// Add a node map reading rule to the reader.
602    template <typename Map>
603    DigraphReader& nodeMap(const std::string& caption, Map& map) {
604      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
605      _reader_bits::MapStorageBase<Node>* storage =
606        new _reader_bits::MapStorage<Node, Map>(map);
607      _node_maps.push_back(std::make_pair(caption, storage));
608      return *this;
609    }
610
611    /// \brief Node map reading rule
612    ///
613    /// Add a node map reading rule with specialized converter to the
614    /// reader.
615    template <typename Map, typename Converter>
616    DigraphReader& nodeMap(const std::string& caption, Map& map,
617                           const Converter& converter = Converter()) {
618      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
619      _reader_bits::MapStorageBase<Node>* storage =
620        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
621      _node_maps.push_back(std::make_pair(caption, storage));
622      return *this;
623    }
624
625    /// \brief Arc map reading rule
626    ///
627    /// Add an arc map reading rule to the reader.
628    template <typename Map>
629    DigraphReader& arcMap(const std::string& caption, Map& map) {
630      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
631      _reader_bits::MapStorageBase<Arc>* storage =
632        new _reader_bits::MapStorage<Arc, Map>(map);
633      _arc_maps.push_back(std::make_pair(caption, storage));
634      return *this;
635    }
636
637    /// \brief Arc map reading rule
638    ///
639    /// Add an arc map reading rule with specialized converter to the
640    /// reader.
641    template <typename Map, typename Converter>
642    DigraphReader& arcMap(const std::string& caption, Map& map,
643                          const Converter& converter = Converter()) {
644      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
645      _reader_bits::MapStorageBase<Arc>* storage =
646        new _reader_bits::MapStorage<Arc, Map, Converter>(map, converter);
647      _arc_maps.push_back(std::make_pair(caption, storage));
648      return *this;
649    }
650
651    /// \brief Attribute reading rule
652    ///
653    /// Add an attribute reading rule to the reader.
654    template <typename Value>
655    DigraphReader& attribute(const std::string& caption, Value& value) {
656      _reader_bits::ValueStorageBase* storage =
657        new _reader_bits::ValueStorage<Value>(value);
658      _attributes.insert(std::make_pair(caption, storage));
659      return *this;
660    }
661
662    /// \brief Attribute reading rule
663    ///
664    /// Add an attribute reading rule with specialized converter to the
665    /// reader.
666    template <typename Value, typename Converter>
667    DigraphReader& attribute(const std::string& caption, Value& value,
668                             const Converter& converter = Converter()) {
669      _reader_bits::ValueStorageBase* storage =
670        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
671      _attributes.insert(std::make_pair(caption, storage));
672      return *this;
673    }
674
675    /// \brief Node reading rule
676    ///
677    /// Add a node reading rule to reader.
678    DigraphReader& node(const std::string& caption, Node& node) {
679      typedef _reader_bits::MapLookUpConverter<Node> Converter;
680      Converter converter(_node_index);
681      _reader_bits::ValueStorageBase* storage =
682        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
683      _attributes.insert(std::make_pair(caption, storage));
684      return *this;
685    }
686
687    /// \brief Arc reading rule
688    ///
689    /// Add an arc reading rule to reader.
690    DigraphReader& arc(const std::string& caption, Arc& arc) {
691      typedef _reader_bits::MapLookUpConverter<Arc> Converter;
692      Converter converter(_arc_index);
693      _reader_bits::ValueStorageBase* storage =
694        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
695      _attributes.insert(std::make_pair(caption, storage));
696      return *this;
697    }
698
699    /// @}
700
701    /// \name Select section by name
702    /// @{
703
704    /// \brief Set \c \@nodes section to be read
705    ///
706    /// Set \c \@nodes section to be read
707    DigraphReader& nodes(const std::string& caption) {
708      _nodes_caption = caption;
709      return *this;
710    }
711
712    /// \brief Set \c \@arcs section to be read
713    ///
714    /// Set \c \@arcs section to be read
715    DigraphReader& arcs(const std::string& caption) {
716      _arcs_caption = caption;
717      return *this;
718    }
719
720    /// \brief Set \c \@attributes section to be read
721    ///
722    /// Set \c \@attributes section to be read
723    DigraphReader& attributes(const std::string& caption) {
724      _attributes_caption = caption;
725      return *this;
726    }
727
728    /// @}
729
730    /// \name Using previously constructed node or arc set
731    /// @{
732
733    /// \brief Use previously constructed node set
734    ///
735    /// Use previously constructed node set, and specify the node
736    /// label map.
737    template <typename Map>
738    DigraphReader& useNodes(const Map& map) {
739      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
740      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
741      _use_nodes = true;
742      _writer_bits::DefaultConverter<typename Map::Value> converter;
743      for (NodeIt n(_digraph); n != INVALID; ++n) {
744        _node_index.insert(std::make_pair(converter(map[n]), n));
745      }
746      return *this;
747    }
748
749    /// \brief Use previously constructed node set
750    ///
751    /// Use previously constructed node set, and specify the node
752    /// label map and a functor which converts the label map values to
753    /// \c std::string.
754    template <typename Map, typename Converter>
755    DigraphReader& useNodes(const Map& map,
756                            const Converter& converter = Converter()) {
757      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
758      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
759      _use_nodes = true;
760      for (NodeIt n(_digraph); n != INVALID; ++n) {
761        _node_index.insert(std::make_pair(converter(map[n]), n));
762      }
763      return *this;
764    }
765
766    /// \brief Use previously constructed arc set
767    ///
768    /// Use previously constructed arc set, and specify the arc
769    /// label map.
770    template <typename Map>
771    DigraphReader& useArcs(const Map& map) {
772      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
773      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
774      _use_arcs = true;
775      _writer_bits::DefaultConverter<typename Map::Value> converter;
776      for (ArcIt a(_digraph); a != INVALID; ++a) {
777        _arc_index.insert(std::make_pair(converter(map[a]), a));
778      }
779      return *this;
780    }
781
782    /// \brief Use previously constructed arc set
783    ///
784    /// Use previously constructed arc set, and specify the arc
785    /// label map and a functor which converts the label map values to
786    /// \c std::string.
787    template <typename Map, typename Converter>
788    DigraphReader& useArcs(const Map& map,
789                           const Converter& converter = Converter()) {
790      checkConcept<concepts::ReadMap<Arc, typename Map::Value>, Map>();
791      LEMON_ASSERT(!_use_arcs, "Multiple usage of useArcs() member");
792      _use_arcs = true;
793      for (ArcIt a(_digraph); a != INVALID; ++a) {
794        _arc_index.insert(std::make_pair(converter(map[a]), a));
795      }
796      return *this;
797    }
798
799    /// \brief Skips the reading of node section
800    ///
801    /// Omit the reading of the node section. This implies that each node
802    /// map reading rule will be abandoned, and the nodes of the graph
803    /// will not be constructed, which usually cause that the arc set
804    /// could not be read due to lack of node name resolving.
805    /// Therefore \c skipArcs() function should also be used, or
806    /// \c useNodes() should be used to specify the label of the nodes.
807    DigraphReader& skipNodes() {
808      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
809      _skip_nodes = true;
810      return *this;
811    }
812
813    /// \brief Skips the reading of arc section
814    ///
815    /// Omit the reading of the arc section. This implies that each arc
816    /// map reading rule will be abandoned, and the arcs of the graph
817    /// will not be constructed.
818    DigraphReader& skipArcs() {
819      LEMON_ASSERT(!_skip_arcs, "Skip arcs already set");
820      _skip_arcs = true;
821      return *this;
822    }
823
824    /// @}
825
826  private:
827
828    bool readLine() {
829      std::string str;
830      while(++line_num, std::getline(*_is, str)) {
831        line.clear(); line.str(str);
832        char c;
833        if (line >> std::ws >> c && c != '#') {
834          line.putback(c);
835          return true;
836        }
837      }
838      return false;
839    }
840
841    bool readSuccess() {
842      return static_cast<bool>(*_is);
843    }
844
845    void skipSection() {
846      char c;
847      while (readSuccess() && line >> c && c != '@') {
848        readLine();
849      }
850      line.putback(c);
851    }
852
853    void readNodes() {
854
855      std::vector<int> map_index(_node_maps.size());
856      int map_num, label_index;
857
858      char c;
859      if (!readLine() || !(line >> c) || c == '@') {
860        if (readSuccess() && line) line.putback(c);
861        if (!_node_maps.empty())
862          throw FormatError("Cannot find map names");
863        return;
864      }
865      line.putback(c);
866
867      {
868        std::map<std::string, int> maps;
869
870        std::string map;
871        int index = 0;
872        while (_reader_bits::readToken(line, map)) {
873          if (maps.find(map) != maps.end()) {
874            std::ostringstream msg;
875            msg << "Multiple occurence of node map: " << map;
876            throw FormatError(msg.str());
877          }
878          maps.insert(std::make_pair(map, index));
879          ++index;
880        }
881
882        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
883          std::map<std::string, int>::iterator jt =
884            maps.find(_node_maps[i].first);
885          if (jt == maps.end()) {
886            std::ostringstream msg;
887            msg << "Map not found: " << _node_maps[i].first;
888            throw FormatError(msg.str());
889          }
890          map_index[i] = jt->second;
891        }
892
893        {
894          std::map<std::string, int>::iterator jt = maps.find("label");
895          if (jt != maps.end()) {
896            label_index = jt->second;
897          } else {
898            label_index = -1;
899          }
900        }
901        map_num = maps.size();
902      }
903
904      while (readLine() && line >> c && c != '@') {
905        line.putback(c);
906
907        std::vector<std::string> tokens(map_num);
908        for (int i = 0; i < map_num; ++i) {
909          if (!_reader_bits::readToken(line, tokens[i])) {
910            std::ostringstream msg;
911            msg << "Column not found (" << i + 1 << ")";
912            throw FormatError(msg.str());
913          }
914        }
915        if (line >> std::ws >> c)
916          throw FormatError("Extra character at the end of line");
917
918        Node n;
919        if (!_use_nodes) {
920          n = _digraph.addNode();
921          if (label_index != -1)
922            _node_index.insert(std::make_pair(tokens[label_index], n));
923        } else {
924          if (label_index == -1)
925            throw FormatError("Label map not found");
926          typename std::map<std::string, Node>::iterator it =
927            _node_index.find(tokens[label_index]);
928          if (it == _node_index.end()) {
929            std::ostringstream msg;
930            msg << "Node with label not found: " << tokens[label_index];
931            throw FormatError(msg.str());
932          }
933          n = it->second;
934        }
935
936        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
937          _node_maps[i].second->set(n, tokens[map_index[i]]);
938        }
939
940      }
941      if (readSuccess()) {
942        line.putback(c);
943      }
944    }
945
946    void readArcs() {
947
948      std::vector<int> map_index(_arc_maps.size());
949      int map_num, label_index;
950
951      char c;
952      if (!readLine() || !(line >> c) || c == '@') {
953        if (readSuccess() && line) line.putback(c);
954        if (!_arc_maps.empty())
955          throw FormatError("Cannot find map names");
956        return;
957      }
958      line.putback(c);
959
960      {
961        std::map<std::string, int> maps;
962
963        std::string map;
964        int index = 0;
965        while (_reader_bits::readToken(line, map)) {
966          if (maps.find(map) != maps.end()) {
967            std::ostringstream msg;
968            msg << "Multiple occurence of arc map: " << map;
969            throw FormatError(msg.str());
970          }
971          maps.insert(std::make_pair(map, index));
972          ++index;
973        }
974
975        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
976          std::map<std::string, int>::iterator jt =
977            maps.find(_arc_maps[i].first);
978          if (jt == maps.end()) {
979            std::ostringstream msg;
980            msg << "Map not found: " << _arc_maps[i].first;
981            throw FormatError(msg.str());
982          }
983          map_index[i] = jt->second;
984        }
985
986        {
987          std::map<std::string, int>::iterator jt = maps.find("label");
988          if (jt != maps.end()) {
989            label_index = jt->second;
990          } else {
991            label_index = -1;
992          }
993        }
994        map_num = maps.size();
995      }
996
997      while (readLine() && line >> c && c != '@') {
998        line.putback(c);
999
1000        std::string source_token;
1001        std::string target_token;
1002
1003        if (!_reader_bits::readToken(line, source_token))
1004          throw FormatError("Source not found");
1005
1006        if (!_reader_bits::readToken(line, target_token))
1007          throw FormatError("Target not found");
1008
1009        std::vector<std::string> tokens(map_num);
1010        for (int i = 0; i < map_num; ++i) {
1011          if (!_reader_bits::readToken(line, tokens[i])) {
1012            std::ostringstream msg;
1013            msg << "Column not found (" << i + 1 << ")";
1014            throw FormatError(msg.str());
1015          }
1016        }
1017        if (line >> std::ws >> c)
1018          throw FormatError("Extra character at the end of line");
1019
1020        Arc a;
1021        if (!_use_arcs) {
1022
1023          typename NodeIndex::iterator it;
1024
1025          it = _node_index.find(source_token);
1026          if (it == _node_index.end()) {
1027            std::ostringstream msg;
1028            msg << "Item not found: " << source_token;
1029            throw FormatError(msg.str());
1030          }
1031          Node source = it->second;
1032
1033          it = _node_index.find(target_token);
1034          if (it == _node_index.end()) {
1035            std::ostringstream msg;
1036            msg << "Item not found: " << target_token;
1037            throw FormatError(msg.str());
1038          }
1039          Node target = it->second;
1040
1041          a = _digraph.addArc(source, target);
1042          if (label_index != -1)
1043            _arc_index.insert(std::make_pair(tokens[label_index], a));
1044        } else {
1045          if (label_index == -1)
1046            throw FormatError("Label map not found");
1047          typename std::map<std::string, Arc>::iterator it =
1048            _arc_index.find(tokens[label_index]);
1049          if (it == _arc_index.end()) {
1050            std::ostringstream msg;
1051            msg << "Arc with label not found: " << tokens[label_index];
1052            throw FormatError(msg.str());
1053          }
1054          a = it->second;
1055        }
1056
1057        for (int i = 0; i < static_cast<int>(_arc_maps.size()); ++i) {
1058          _arc_maps[i].second->set(a, tokens[map_index[i]]);
1059        }
1060
1061      }
1062      if (readSuccess()) {
1063        line.putback(c);
1064      }
1065    }
1066
1067    void readAttributes() {
1068
1069      std::set<std::string> read_attr;
1070
1071      char c;
1072      while (readLine() && line >> c && c != '@') {
1073        line.putback(c);
1074
1075        std::string attr, token;
1076        if (!_reader_bits::readToken(line, attr))
1077          throw FormatError("Attribute name not found");
1078        if (!_reader_bits::readToken(line, token))
1079          throw FormatError("Attribute value not found");
1080        if (line >> c)
1081          throw FormatError("Extra character at the end of line");
1082
1083        {
1084          std::set<std::string>::iterator it = read_attr.find(attr);
1085          if (it != read_attr.end()) {
1086            std::ostringstream msg;
1087            msg << "Multiple occurence of attribute: " << attr;
1088            throw FormatError(msg.str());
1089          }
1090          read_attr.insert(attr);
1091        }
1092
1093        {
1094          typename Attributes::iterator it = _attributes.lower_bound(attr);
1095          while (it != _attributes.end() && it->first == attr) {
1096            it->second->set(token);
1097            ++it;
1098          }
1099        }
1100
1101      }
1102      if (readSuccess()) {
1103        line.putback(c);
1104      }
1105      for (typename Attributes::iterator it = _attributes.begin();
1106           it != _attributes.end(); ++it) {
1107        if (read_attr.find(it->first) == read_attr.end()) {
1108          std::ostringstream msg;
1109          msg << "Attribute not found: " << it->first;
1110          throw FormatError(msg.str());
1111        }
1112      }
1113    }
1114
1115  public:
1116
1117    /// \name Execution of the reader
1118    /// @{
1119
1120    /// \brief Start the batch processing
1121    ///
1122    /// This function starts the batch processing
1123    void run() {
1124      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1125
1126      bool nodes_done = _skip_nodes;
1127      bool arcs_done = _skip_arcs;
1128      bool attributes_done = false;
1129
1130      line_num = 0;
1131      readLine();
1132      skipSection();
1133
1134      while (readSuccess()) {
1135        try {
1136          char c;
1137          std::string section, caption;
1138          line >> c;
1139          _reader_bits::readToken(line, section);
1140          _reader_bits::readToken(line, caption);
1141
1142          if (line >> c)
1143            throw FormatError("Extra character at the end of line");
1144
1145          if (section == "nodes" && !nodes_done) {
1146            if (_nodes_caption.empty() || _nodes_caption == caption) {
1147              readNodes();
1148              nodes_done = true;
1149            }
1150          } else if ((section == "arcs" || section == "edges") &&
1151                     !arcs_done) {
1152            if (_arcs_caption.empty() || _arcs_caption == caption) {
1153              readArcs();
1154              arcs_done = true;
1155            }
1156          } else if (section == "attributes" && !attributes_done) {
1157            if (_attributes_caption.empty() || _attributes_caption == caption) {
1158              readAttributes();
1159              attributes_done = true;
1160            }
1161          } else {
1162            readLine();
1163            skipSection();
1164          }
1165        } catch (FormatError& error) {
1166          error.line(line_num);
1167          error.file(_filename);
1168          throw;
1169        }
1170      }
1171
1172      if (!nodes_done) {
1173        throw FormatError("Section @nodes not found");
1174      }
1175
1176      if (!arcs_done) {
1177        throw FormatError("Section @arcs not found");
1178      }
1179
1180      if (!attributes_done && !_attributes.empty()) {
1181        throw FormatError("Section @attributes not found");
1182      }
1183
1184    }
1185
1186    /// @}
1187
1188  };
1189
1190  /// \brief Return a \ref DigraphReader class
1191  ///
1192  /// This function just returns a \ref DigraphReader class.
1193  /// \relates DigraphReader
1194  template <typename Digraph>
1195  DigraphReader<Digraph> digraphReader(Digraph& digraph, std::istream& is) {
1196    DigraphReader<Digraph> tmp(digraph, is);
1197    return tmp;
1198  }
1199
1200  /// \brief Return a \ref DigraphReader class
1201  ///
1202  /// This function just returns a \ref DigraphReader class.
1203  /// \relates DigraphReader
1204  template <typename Digraph>
1205  DigraphReader<Digraph> digraphReader(Digraph& digraph,
1206                                       const std::string& fn) {
1207    DigraphReader<Digraph> tmp(digraph, fn);
1208    return tmp;
1209  }
1210
1211  /// \brief Return a \ref DigraphReader class
1212  ///
1213  /// This function just returns a \ref DigraphReader class.
1214  /// \relates DigraphReader
1215  template <typename Digraph>
1216  DigraphReader<Digraph> digraphReader(Digraph& digraph, const char* fn) {
1217    DigraphReader<Digraph> tmp(digraph, fn);
1218    return tmp;
1219  }
1220
1221  template <typename Graph>
1222  class GraphReader;
1223 
1224  template <typename Graph>
1225  GraphReader<Graph> graphReader(Graph& graph,
1226                                 std::istream& is = std::cin);
1227  template <typename Graph>
1228  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn);
1229  template <typename Graph>
1230  GraphReader<Graph> graphReader(Graph& graph, const char *fn);
1231
1232  /// \ingroup lemon_io
1233  ///
1234  /// \brief \ref lgf-format "LGF" reader for undirected graphs
1235  ///
1236  /// This utility reads an \ref lgf-format "LGF" file.
1237  ///
1238  /// It can be used almost the same way as \c DigraphReader.
1239  /// The only difference is that this class can handle edges and
1240  /// edge maps as well as arcs and arc maps.
1241  ///
1242  /// The columns in the \c \@edges (or \c \@arcs) section are the
1243  /// edge maps. However, if there are two maps with the same name
1244  /// prefixed with \c '+' and \c '-', then these can be read into an
1245  /// arc map.  Similarly, an attribute can be read into an arc, if
1246  /// it's value is an edge label prefixed with \c '+' or \c '-'.
1247  template <typename _Graph>
1248  class GraphReader {
1249  public:
1250
1251    typedef _Graph Graph;
1252    TEMPLATE_GRAPH_TYPEDEFS(Graph);
1253
1254  private:
1255
1256    std::istream* _is;
1257    bool local_is;
1258    std::string _filename;
1259
1260    Graph& _graph;
1261
1262    std::string _nodes_caption;
1263    std::string _edges_caption;
1264    std::string _attributes_caption;
1265
1266    typedef std::map<std::string, Node> NodeIndex;
1267    NodeIndex _node_index;
1268    typedef std::map<std::string, Edge> EdgeIndex;
1269    EdgeIndex _edge_index;
1270
1271    typedef std::vector<std::pair<std::string,
1272      _reader_bits::MapStorageBase<Node>*> > NodeMaps;
1273    NodeMaps _node_maps;
1274
1275    typedef std::vector<std::pair<std::string,
1276      _reader_bits::MapStorageBase<Edge>*> > EdgeMaps;
1277    EdgeMaps _edge_maps;
1278
1279    typedef std::multimap<std::string, _reader_bits::ValueStorageBase*>
1280      Attributes;
1281    Attributes _attributes;
1282
1283    bool _use_nodes;
1284    bool _use_edges;
1285
1286    bool _skip_nodes;
1287    bool _skip_edges;
1288
1289    int line_num;
1290    std::istringstream line;
1291
1292  public:
1293
1294    /// \brief Constructor
1295    ///
1296    /// Construct an undirected graph reader, which reads from the given
1297    /// input stream.
1298    GraphReader(Graph& graph, std::istream& is = std::cin)
1299      : _is(&is), local_is(false), _graph(graph),
1300        _use_nodes(false), _use_edges(false),
1301        _skip_nodes(false), _skip_edges(false) {}
1302
1303    /// \brief Constructor
1304    ///
1305    /// Construct an undirected graph reader, which reads from the given
1306    /// file.
1307    GraphReader(Graph& graph, const std::string& fn)
1308      : _is(new std::ifstream(fn.c_str())), local_is(true),
1309        _filename(fn), _graph(graph),
1310        _use_nodes(false), _use_edges(false),
1311        _skip_nodes(false), _skip_edges(false) {
1312      if (!(*_is)) {
1313        delete _is;
1314        throw IoError("Cannot open file", fn);
1315      }
1316    }
1317
1318    /// \brief Constructor
1319    ///
1320    /// Construct an undirected graph reader, which reads from the given
1321    /// file.
1322    GraphReader(Graph& graph, const char* fn)
1323      : _is(new std::ifstream(fn)), local_is(true),
1324        _filename(fn), _graph(graph),
1325        _use_nodes(false), _use_edges(false),
1326        _skip_nodes(false), _skip_edges(false) {
1327      if (!(*_is)) {
1328        delete _is;
1329        throw IoError("Cannot open file", fn);
1330      }
1331    }
1332
1333    /// \brief Destructor
1334    ~GraphReader() {
1335      for (typename NodeMaps::iterator it = _node_maps.begin();
1336           it != _node_maps.end(); ++it) {
1337        delete it->second;
1338      }
1339
1340      for (typename EdgeMaps::iterator it = _edge_maps.begin();
1341           it != _edge_maps.end(); ++it) {
1342        delete it->second;
1343      }
1344
1345      for (typename Attributes::iterator it = _attributes.begin();
1346           it != _attributes.end(); ++it) {
1347        delete it->second;
1348      }
1349
1350      if (local_is) {
1351        delete _is;
1352      }
1353
1354    }
1355
1356  private:
1357    template <typename GR>
1358    friend GraphReader<GR> graphReader(GR& graph, std::istream& is);
1359    template <typename GR>
1360    friend GraphReader<GR> graphReader(GR& graph, const std::string& fn);
1361    template <typename GR>
1362    friend GraphReader<GR> graphReader(GR& graph, const char *fn);
1363
1364    GraphReader(GraphReader& other)
1365      : _is(other._is), local_is(other.local_is), _graph(other._graph),
1366        _use_nodes(other._use_nodes), _use_edges(other._use_edges),
1367        _skip_nodes(other._skip_nodes), _skip_edges(other._skip_edges) {
1368
1369      other._is = 0;
1370      other.local_is = false;
1371
1372      _node_index.swap(other._node_index);
1373      _edge_index.swap(other._edge_index);
1374
1375      _node_maps.swap(other._node_maps);
1376      _edge_maps.swap(other._edge_maps);
1377      _attributes.swap(other._attributes);
1378
1379      _nodes_caption = other._nodes_caption;
1380      _edges_caption = other._edges_caption;
1381      _attributes_caption = other._attributes_caption;
1382
1383    }
1384
1385    GraphReader& operator=(const GraphReader&);
1386
1387  public:
1388
1389    /// \name Reading rules
1390    /// @{
1391
1392    /// \brief Node map reading rule
1393    ///
1394    /// Add a node map reading rule to the reader.
1395    template <typename Map>
1396    GraphReader& nodeMap(const std::string& caption, Map& map) {
1397      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1398      _reader_bits::MapStorageBase<Node>* storage =
1399        new _reader_bits::MapStorage<Node, Map>(map);
1400      _node_maps.push_back(std::make_pair(caption, storage));
1401      return *this;
1402    }
1403
1404    /// \brief Node map reading rule
1405    ///
1406    /// Add a node map reading rule with specialized converter to the
1407    /// reader.
1408    template <typename Map, typename Converter>
1409    GraphReader& nodeMap(const std::string& caption, Map& map,
1410                           const Converter& converter = Converter()) {
1411      checkConcept<concepts::WriteMap<Node, typename Map::Value>, Map>();
1412      _reader_bits::MapStorageBase<Node>* storage =
1413        new _reader_bits::MapStorage<Node, Map, Converter>(map, converter);
1414      _node_maps.push_back(std::make_pair(caption, storage));
1415      return *this;
1416    }
1417
1418    /// \brief Edge map reading rule
1419    ///
1420    /// Add an edge map reading rule to the reader.
1421    template <typename Map>
1422    GraphReader& edgeMap(const std::string& caption, Map& map) {
1423      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1424      _reader_bits::MapStorageBase<Edge>* storage =
1425        new _reader_bits::MapStorage<Edge, Map>(map);
1426      _edge_maps.push_back(std::make_pair(caption, storage));
1427      return *this;
1428    }
1429
1430    /// \brief Edge map reading rule
1431    ///
1432    /// Add an edge map reading rule with specialized converter to the
1433    /// reader.
1434    template <typename Map, typename Converter>
1435    GraphReader& edgeMap(const std::string& caption, Map& map,
1436                          const Converter& converter = Converter()) {
1437      checkConcept<concepts::WriteMap<Edge, typename Map::Value>, Map>();
1438      _reader_bits::MapStorageBase<Edge>* storage =
1439        new _reader_bits::MapStorage<Edge, Map, Converter>(map, converter);
1440      _edge_maps.push_back(std::make_pair(caption, storage));
1441      return *this;
1442    }
1443
1444    /// \brief Arc map reading rule
1445    ///
1446    /// Add an arc map reading rule to the reader.
1447    template <typename Map>
1448    GraphReader& arcMap(const std::string& caption, Map& map) {
1449      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1450      _reader_bits::MapStorageBase<Edge>* forward_storage =
1451        new _reader_bits::GraphArcMapStorage<Graph, true, Map>(_graph, map);
1452      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1453      _reader_bits::MapStorageBase<Edge>* backward_storage =
1454        new _reader_bits::GraphArcMapStorage<Graph, false, Map>(_graph, map);
1455      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1456      return *this;
1457    }
1458
1459    /// \brief Arc map reading rule
1460    ///
1461    /// Add an arc map reading rule with specialized converter to the
1462    /// reader.
1463    template <typename Map, typename Converter>
1464    GraphReader& arcMap(const std::string& caption, Map& map,
1465                          const Converter& converter = Converter()) {
1466      checkConcept<concepts::WriteMap<Arc, typename Map::Value>, Map>();
1467      _reader_bits::MapStorageBase<Edge>* forward_storage =
1468        new _reader_bits::GraphArcMapStorage<Graph, true, Map, Converter>
1469        (_graph, map, converter);
1470      _edge_maps.push_back(std::make_pair('+' + caption, forward_storage));
1471      _reader_bits::MapStorageBase<Edge>* backward_storage =
1472        new _reader_bits::GraphArcMapStorage<Graph, false, Map, Converter>
1473        (_graph, map, converter);
1474      _edge_maps.push_back(std::make_pair('-' + caption, backward_storage));
1475      return *this;
1476    }
1477
1478    /// \brief Attribute reading rule
1479    ///
1480    /// Add an attribute reading rule to the reader.
1481    template <typename Value>
1482    GraphReader& attribute(const std::string& caption, Value& value) {
1483      _reader_bits::ValueStorageBase* storage =
1484        new _reader_bits::ValueStorage<Value>(value);
1485      _attributes.insert(std::make_pair(caption, storage));
1486      return *this;
1487    }
1488
1489    /// \brief Attribute reading rule
1490    ///
1491    /// Add an attribute reading rule with specialized converter to the
1492    /// reader.
1493    template <typename Value, typename Converter>
1494    GraphReader& attribute(const std::string& caption, Value& value,
1495                             const Converter& converter = Converter()) {
1496      _reader_bits::ValueStorageBase* storage =
1497        new _reader_bits::ValueStorage<Value, Converter>(value, converter);
1498      _attributes.insert(std::make_pair(caption, storage));
1499      return *this;
1500    }
1501
1502    /// \brief Node reading rule
1503    ///
1504    /// Add a node reading rule to reader.
1505    GraphReader& node(const std::string& caption, Node& node) {
1506      typedef _reader_bits::MapLookUpConverter<Node> Converter;
1507      Converter converter(_node_index);
1508      _reader_bits::ValueStorageBase* storage =
1509        new _reader_bits::ValueStorage<Node, Converter>(node, converter);
1510      _attributes.insert(std::make_pair(caption, storage));
1511      return *this;
1512    }
1513
1514    /// \brief Edge reading rule
1515    ///
1516    /// Add an edge reading rule to reader.
1517    GraphReader& edge(const std::string& caption, Edge& edge) {
1518      typedef _reader_bits::MapLookUpConverter<Edge> Converter;
1519      Converter converter(_edge_index);
1520      _reader_bits::ValueStorageBase* storage =
1521        new _reader_bits::ValueStorage<Edge, Converter>(edge, converter);
1522      _attributes.insert(std::make_pair(caption, storage));
1523      return *this;
1524    }
1525
1526    /// \brief Arc reading rule
1527    ///
1528    /// Add an arc reading rule to reader.
1529    GraphReader& arc(const std::string& caption, Arc& arc) {
1530      typedef _reader_bits::GraphArcLookUpConverter<Graph> Converter;
1531      Converter converter(_graph, _edge_index);
1532      _reader_bits::ValueStorageBase* storage =
1533        new _reader_bits::ValueStorage<Arc, Converter>(arc, converter);
1534      _attributes.insert(std::make_pair(caption, storage));
1535      return *this;
1536    }
1537
1538    /// @}
1539
1540    /// \name Select section by name
1541    /// @{
1542
1543    /// \brief Set \c \@nodes section to be read
1544    ///
1545    /// Set \c \@nodes section to be read.
1546    GraphReader& nodes(const std::string& caption) {
1547      _nodes_caption = caption;
1548      return *this;
1549    }
1550
1551    /// \brief Set \c \@edges section to be read
1552    ///
1553    /// Set \c \@edges section to be read.
1554    GraphReader& edges(const std::string& caption) {
1555      _edges_caption = caption;
1556      return *this;
1557    }
1558
1559    /// \brief Set \c \@attributes section to be read
1560    ///
1561    /// Set \c \@attributes section to be read.
1562    GraphReader& attributes(const std::string& caption) {
1563      _attributes_caption = caption;
1564      return *this;
1565    }
1566
1567    /// @}
1568
1569    /// \name Using previously constructed node or edge set
1570    /// @{
1571
1572    /// \brief Use previously constructed node set
1573    ///
1574    /// Use previously constructed node set, and specify the node
1575    /// label map.
1576    template <typename Map>
1577    GraphReader& useNodes(const Map& map) {
1578      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1579      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1580      _use_nodes = true;
1581      _writer_bits::DefaultConverter<typename Map::Value> converter;
1582      for (NodeIt n(_graph); n != INVALID; ++n) {
1583        _node_index.insert(std::make_pair(converter(map[n]), n));
1584      }
1585      return *this;
1586    }
1587
1588    /// \brief Use previously constructed node set
1589    ///
1590    /// Use previously constructed node set, and specify the node
1591    /// label map and a functor which converts the label map values to
1592    /// \c std::string.
1593    template <typename Map, typename Converter>
1594    GraphReader& useNodes(const Map& map,
1595                            const Converter& converter = Converter()) {
1596      checkConcept<concepts::ReadMap<Node, typename Map::Value>, Map>();
1597      LEMON_ASSERT(!_use_nodes, "Multiple usage of useNodes() member");
1598      _use_nodes = true;
1599      for (NodeIt n(_graph); n != INVALID; ++n) {
1600        _node_index.insert(std::make_pair(converter(map[n]), n));
1601      }
1602      return *this;
1603    }
1604
1605    /// \brief Use previously constructed edge set
1606    ///
1607    /// Use previously constructed edge set, and specify the edge
1608    /// label map.
1609    template <typename Map>
1610    GraphReader& useEdges(const Map& map) {
1611      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1612      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1613      _use_edges = true;
1614      _writer_bits::DefaultConverter<typename Map::Value> converter;
1615      for (EdgeIt a(_graph); a != INVALID; ++a) {
1616        _edge_index.insert(std::make_pair(converter(map[a]), a));
1617      }
1618      return *this;
1619    }
1620
1621    /// \brief Use previously constructed edge set
1622    ///
1623    /// Use previously constructed edge set, and specify the edge
1624    /// label map and a functor which converts the label map values to
1625    /// \c std::string.
1626    template <typename Map, typename Converter>
1627    GraphReader& useEdges(const Map& map,
1628                            const Converter& converter = Converter()) {
1629      checkConcept<concepts::ReadMap<Edge, typename Map::Value>, Map>();
1630      LEMON_ASSERT(!_use_edges, "Multiple usage of useEdges() member");
1631      _use_edges = true;
1632      for (EdgeIt a(_graph); a != INVALID; ++a) {
1633        _edge_index.insert(std::make_pair(converter(map[a]), a));
1634      }
1635      return *this;
1636    }
1637
1638    /// \brief Skip the reading of node section
1639    ///
1640    /// Omit the reading of the node section. This implies that each node
1641    /// map reading rule will be abandoned, and the nodes of the graph
1642    /// will not be constructed, which usually cause that the edge set
1643    /// could not be read due to lack of node name
1644    /// could not be read due to lack of node name resolving.
1645    /// Therefore \c skipEdges() function should also be used, or
1646    /// \c useNodes() should be used to specify the label of the nodes.
1647    GraphReader& skipNodes() {
1648      LEMON_ASSERT(!_skip_nodes, "Skip nodes already set");
1649      _skip_nodes = true;
1650      return *this;
1651    }
1652
1653    /// \brief Skip the reading of edge section
1654    ///
1655    /// Omit the reading of the edge section. This implies that each edge
1656    /// map reading rule will be abandoned, and the edges of the graph
1657    /// will not be constructed.
1658    GraphReader& skipEdges() {
1659      LEMON_ASSERT(!_skip_edges, "Skip edges already set");
1660      _skip_edges = true;
1661      return *this;
1662    }
1663
1664    /// @}
1665
1666  private:
1667
1668    bool readLine() {
1669      std::string str;
1670      while(++line_num, std::getline(*_is, str)) {
1671        line.clear(); line.str(str);
1672        char c;
1673        if (line >> std::ws >> c && c != '#') {
1674          line.putback(c);
1675          return true;
1676        }
1677      }
1678      return false;
1679    }
1680
1681    bool readSuccess() {
1682      return static_cast<bool>(*_is);
1683    }
1684
1685    void skipSection() {
1686      char c;
1687      while (readSuccess() && line >> c && c != '@') {
1688        readLine();
1689      }
1690      line.putback(c);
1691    }
1692
1693    void readNodes() {
1694
1695      std::vector<int> map_index(_node_maps.size());
1696      int map_num, label_index;
1697
1698      char c;
1699      if (!readLine() || !(line >> c) || c == '@') {
1700        if (readSuccess() && line) line.putback(c);
1701        if (!_node_maps.empty())
1702          throw FormatError("Cannot find map names");
1703        return;
1704      }
1705      line.putback(c);
1706
1707      {
1708        std::map<std::string, int> maps;
1709
1710        std::string map;
1711        int index = 0;
1712        while (_reader_bits::readToken(line, map)) {
1713          if (maps.find(map) != maps.end()) {
1714            std::ostringstream msg;
1715            msg << "Multiple occurence of node map: " << map;
1716            throw FormatError(msg.str());
1717          }
1718          maps.insert(std::make_pair(map, index));
1719          ++index;
1720        }
1721
1722        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1723          std::map<std::string, int>::iterator jt =
1724            maps.find(_node_maps[i].first);
1725          if (jt == maps.end()) {
1726            std::ostringstream msg;
1727            msg << "Map not found: " << _node_maps[i].first;
1728            throw FormatError(msg.str());
1729          }
1730          map_index[i] = jt->second;
1731        }
1732
1733        {
1734          std::map<std::string, int>::iterator jt = maps.find("label");
1735          if (jt != maps.end()) {
1736            label_index = jt->second;
1737          } else {
1738            label_index = -1;
1739          }
1740        }
1741        map_num = maps.size();
1742      }
1743
1744      while (readLine() && line >> c && c != '@') {
1745        line.putback(c);
1746
1747        std::vector<std::string> tokens(map_num);
1748        for (int i = 0; i < map_num; ++i) {
1749          if (!_reader_bits::readToken(line, tokens[i])) {
1750            std::ostringstream msg;
1751            msg << "Column not found (" << i + 1 << ")";
1752            throw FormatError(msg.str());
1753          }
1754        }
1755        if (line >> std::ws >> c)
1756          throw FormatError("Extra character at the end of line");
1757
1758        Node n;
1759        if (!_use_nodes) {
1760          n = _graph.addNode();
1761          if (label_index != -1)
1762            _node_index.insert(std::make_pair(tokens[label_index], n));
1763        } else {
1764          if (label_index == -1)
1765            throw FormatError("Label map not found");
1766          typename std::map<std::string, Node>::iterator it =
1767            _node_index.find(tokens[label_index]);
1768          if (it == _node_index.end()) {
1769            std::ostringstream msg;
1770            msg << "Node with label not found: " << tokens[label_index];
1771            throw FormatError(msg.str());
1772          }
1773          n = it->second;
1774        }
1775
1776        for (int i = 0; i < static_cast<int>(_node_maps.size()); ++i) {
1777          _node_maps[i].second->set(n, tokens[map_index[i]]);
1778        }
1779
1780      }
1781      if (readSuccess()) {
1782        line.putback(c);
1783      }
1784    }
1785
1786    void readEdges() {
1787
1788      std::vector<int> map_index(_edge_maps.size());
1789      int map_num, label_index;
1790
1791      char c;
1792      if (!readLine() || !(line >> c) || c == '@') {
1793        if (readSuccess() && line) line.putback(c);
1794        if (!_edge_maps.empty())
1795          throw FormatError("Cannot find map names");
1796        return;
1797      }
1798      line.putback(c);
1799
1800      {
1801        std::map<std::string, int> maps;
1802
1803        std::string map;
1804        int index = 0;
1805        while (_reader_bits::readToken(line, map)) {
1806          if (maps.find(map) != maps.end()) {
1807            std::ostringstream msg;
1808            msg << "Multiple occurence of edge map: " << map;
1809            throw FormatError(msg.str());
1810          }
1811          maps.insert(std::make_pair(map, index));
1812          ++index;
1813        }
1814
1815        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1816          std::map<std::string, int>::iterator jt =
1817            maps.find(_edge_maps[i].first);
1818          if (jt == maps.end()) {
1819            std::ostringstream msg;
1820            msg << "Map not found: " << _edge_maps[i].first;
1821            throw FormatError(msg.str());
1822          }
1823          map_index[i] = jt->second;
1824        }
1825
1826        {
1827          std::map<std::string, int>::iterator jt = maps.find("label");
1828          if (jt != maps.end()) {
1829            label_index = jt->second;
1830          } else {
1831            label_index = -1;
1832          }
1833        }
1834        map_num = maps.size();
1835      }
1836
1837      while (readLine() && line >> c && c != '@') {
1838        line.putback(c);
1839
1840        std::string source_token;
1841        std::string target_token;
1842
1843        if (!_reader_bits::readToken(line, source_token))
1844          throw FormatError("Node u not found");
1845
1846        if (!_reader_bits::readToken(line, target_token))
1847          throw FormatError("Node v not found");
1848
1849        std::vector<std::string> tokens(map_num);
1850        for (int i = 0; i < map_num; ++i) {
1851          if (!_reader_bits::readToken(line, tokens[i])) {
1852            std::ostringstream msg;
1853            msg << "Column not found (" << i + 1 << ")";
1854            throw FormatError(msg.str());
1855          }
1856        }
1857        if (line >> std::ws >> c)
1858          throw FormatError("Extra character at the end of line");
1859
1860        Edge e;
1861        if (!_use_edges) {
1862
1863          typename NodeIndex::iterator it;
1864
1865          it = _node_index.find(source_token);
1866          if (it == _node_index.end()) {
1867            std::ostringstream msg;
1868            msg << "Item not found: " << source_token;
1869            throw FormatError(msg.str());
1870          }
1871          Node source = it->second;
1872
1873          it = _node_index.find(target_token);
1874          if (it == _node_index.end()) {
1875            std::ostringstream msg;
1876            msg << "Item not found: " << target_token;
1877            throw FormatError(msg.str());
1878          }
1879          Node target = it->second;
1880
1881          e = _graph.addEdge(source, target);
1882          if (label_index != -1)
1883            _edge_index.insert(std::make_pair(tokens[label_index], e));
1884        } else {
1885          if (label_index == -1)
1886            throw FormatError("Label map not found");
1887          typename std::map<std::string, Edge>::iterator it =
1888            _edge_index.find(tokens[label_index]);
1889          if (it == _edge_index.end()) {
1890            std::ostringstream msg;
1891            msg << "Edge with label not found: " << tokens[label_index];
1892            throw FormatError(msg.str());
1893          }
1894          e = it->second;
1895        }
1896
1897        for (int i = 0; i < static_cast<int>(_edge_maps.size()); ++i) {
1898          _edge_maps[i].second->set(e, tokens[map_index[i]]);
1899        }
1900
1901      }
1902      if (readSuccess()) {
1903        line.putback(c);
1904      }
1905    }
1906
1907    void readAttributes() {
1908
1909      std::set<std::string> read_attr;
1910
1911      char c;
1912      while (readLine() && line >> c && c != '@') {
1913        line.putback(c);
1914
1915        std::string attr, token;
1916        if (!_reader_bits::readToken(line, attr))
1917          throw FormatError("Attribute name not found");
1918        if (!_reader_bits::readToken(line, token))
1919          throw FormatError("Attribute value not found");
1920        if (line >> c)
1921          throw FormatError("Extra character at the end of line");
1922
1923        {
1924          std::set<std::string>::iterator it = read_attr.find(attr);
1925          if (it != read_attr.end()) {
1926            std::ostringstream msg;
1927            msg << "Multiple occurence of attribute: " << attr;
1928            throw FormatError(msg.str());
1929          }
1930          read_attr.insert(attr);
1931        }
1932
1933        {
1934          typename Attributes::iterator it = _attributes.lower_bound(attr);
1935          while (it != _attributes.end() && it->first == attr) {
1936            it->second->set(token);
1937            ++it;
1938          }
1939        }
1940
1941      }
1942      if (readSuccess()) {
1943        line.putback(c);
1944      }
1945      for (typename Attributes::iterator it = _attributes.begin();
1946           it != _attributes.end(); ++it) {
1947        if (read_attr.find(it->first) == read_attr.end()) {
1948          std::ostringstream msg;
1949          msg << "Attribute not found: " << it->first;
1950          throw FormatError(msg.str());
1951        }
1952      }
1953    }
1954
1955  public:
1956
1957    /// \name Execution of the reader
1958    /// @{
1959
1960    /// \brief Start the batch processing
1961    ///
1962    /// This function starts the batch processing
1963    void run() {
1964
1965      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
1966
1967      bool nodes_done = _skip_nodes;
1968      bool edges_done = _skip_edges;
1969      bool attributes_done = false;
1970
1971      line_num = 0;
1972      readLine();
1973      skipSection();
1974
1975      while (readSuccess()) {
1976        try {
1977          char c;
1978          std::string section, caption;
1979          line >> c;
1980          _reader_bits::readToken(line, section);
1981          _reader_bits::readToken(line, caption);
1982
1983          if (line >> c)
1984            throw FormatError("Extra character at the end of line");
1985
1986          if (section == "nodes" && !nodes_done) {
1987            if (_nodes_caption.empty() || _nodes_caption == caption) {
1988              readNodes();
1989              nodes_done = true;
1990            }
1991          } else if ((section == "edges" || section == "arcs") &&
1992                     !edges_done) {
1993            if (_edges_caption.empty() || _edges_caption == caption) {
1994              readEdges();
1995              edges_done = true;
1996            }
1997          } else if (section == "attributes" && !attributes_done) {
1998            if (_attributes_caption.empty() || _attributes_caption == caption) {
1999              readAttributes();
2000              attributes_done = true;
2001            }
2002          } else {
2003            readLine();
2004            skipSection();
2005          }
2006        } catch (FormatError& error) {
2007          error.line(line_num);
2008          error.file(_filename);
2009          throw;
2010        }
2011      }
2012
2013      if (!nodes_done) {
2014        throw FormatError("Section @nodes not found");
2015      }
2016
2017      if (!edges_done) {
2018        throw FormatError("Section @edges not found");
2019      }
2020
2021      if (!attributes_done && !_attributes.empty()) {
2022        throw FormatError("Section @attributes not found");
2023      }
2024
2025    }
2026
2027    /// @}
2028
2029  };
2030
2031  /// \brief Return a \ref GraphReader class
2032  ///
2033  /// This function just returns a \ref GraphReader class.
2034  /// \relates GraphReader
2035  template <typename Graph>
2036  GraphReader<Graph> graphReader(Graph& graph, std::istream& is) {
2037    GraphReader<Graph> tmp(graph, is);
2038    return tmp;
2039  }
2040
2041  /// \brief Return a \ref GraphReader class
2042  ///
2043  /// This function just returns a \ref GraphReader class.
2044  /// \relates GraphReader
2045  template <typename Graph>
2046  GraphReader<Graph> graphReader(Graph& graph, const std::string& fn) {
2047    GraphReader<Graph> tmp(graph, fn);
2048    return tmp;
2049  }
2050
2051  /// \brief Return a \ref GraphReader class
2052  ///
2053  /// This function just returns a \ref GraphReader class.
2054  /// \relates GraphReader
2055  template <typename Graph>
2056  GraphReader<Graph> graphReader(Graph& graph, const char* fn) {
2057    GraphReader<Graph> tmp(graph, fn);
2058    return tmp;
2059  }
2060
2061  class SectionReader;
2062
2063  SectionReader sectionReader(std::istream& is);
2064  SectionReader sectionReader(const std::string& fn);
2065  SectionReader sectionReader(const char* fn);
2066
2067  /// \ingroup lemon_io
2068  ///
2069  /// \brief Section reader class
2070  ///
2071  /// In the \ref lgf-format "LGF" file extra sections can be placed,
2072  /// which contain any data in arbitrary format. Such sections can be
2073  /// read with this class. A reading rule can be added to the class
2074  /// with two different functions. With the \c sectionLines() function a
2075  /// functor can process the section line-by-line, while with the \c
2076  /// sectionStream() member the section can be read from an input
2077  /// stream.
2078  class SectionReader {
2079  private:
2080
2081    std::istream* _is;
2082    bool local_is;
2083    std::string _filename;
2084
2085    typedef std::map<std::string, _reader_bits::Section*> Sections;
2086    Sections _sections;
2087
2088    int line_num;
2089    std::istringstream line;
2090
2091  public:
2092
2093    /// \brief Constructor
2094    ///
2095    /// Construct a section reader, which reads from the given input
2096    /// stream.
2097    SectionReader(std::istream& is)
2098      : _is(&is), local_is(false) {}
2099
2100    /// \brief Constructor
2101    ///
2102    /// Construct a section reader, which reads from the given file.
2103    SectionReader(const std::string& fn)
2104      : _is(new std::ifstream(fn.c_str())), local_is(true),
2105        _filename(fn) {
2106      if (!(*_is)) {
2107        delete _is;
2108        throw IoError("Cannot open file", fn);
2109      }
2110    }
2111
2112    /// \brief Constructor
2113    ///
2114    /// Construct a section reader, which reads from the given file.
2115    SectionReader(const char* fn)
2116      : _is(new std::ifstream(fn)), local_is(true),
2117        _filename(fn) {
2118      if (!(*_is)) {
2119        delete _is;
2120        throw IoError("Cannot open file", fn);
2121      }
2122    }
2123
2124    /// \brief Destructor
2125    ~SectionReader() {
2126      for (Sections::iterator it = _sections.begin();
2127           it != _sections.end(); ++it) {
2128        delete it->second;
2129      }
2130
2131      if (local_is) {
2132        delete _is;
2133      }
2134
2135    }
2136
2137  private:
2138
2139    friend SectionReader sectionReader(std::istream& is);
2140    friend SectionReader sectionReader(const std::string& fn);
2141    friend SectionReader sectionReader(const char* fn);
2142
2143    SectionReader(SectionReader& other)
2144      : _is(other._is), local_is(other.local_is) {
2145
2146      other._is = 0;
2147      other.local_is = false;
2148
2149      _sections.swap(other._sections);
2150    }
2151
2152    SectionReader& operator=(const SectionReader&);
2153
2154  public:
2155
2156    /// \name Section readers
2157    /// @{
2158
2159    /// \brief Add a section processor with line oriented reading
2160    ///
2161    /// The first parameter is the type descriptor of the section, the
2162    /// second is a functor, which takes just one \c std::string
2163    /// parameter. At the reading process, each line of the section
2164    /// will be given to the functor object. However, the empty lines
2165    /// and the comment lines are filtered out, and the leading
2166    /// whitespaces are trimmed from each processed string.
2167    ///
2168    /// For example let's see a section, which contain several
2169    /// integers, which should be inserted into a vector.
2170    ///\code
2171    ///  @numbers
2172    ///  12 45 23
2173    ///  4
2174    ///  23 6
2175    ///\endcode
2176    ///
2177    /// The functor is implemented as a struct:
2178    ///\code
2179    ///  struct NumberSection {
2180    ///    std::vector<int>& _data;
2181    ///    NumberSection(std::vector<int>& data) : _data(data) {}
2182    ///    void operator()(const std::string& line) {
2183    ///      std::istringstream ls(line);
2184    ///      int value;
2185    ///      while (ls >> value) _data.push_back(value);
2186    ///    }
2187    ///  };
2188    ///
2189    ///  // ...
2190    ///
2191    ///  reader.sectionLines("numbers", NumberSection(vec));
2192    ///\endcode
2193    template <typename Functor>
2194    SectionReader& sectionLines(const std::string& type, Functor functor) {
2195      LEMON_ASSERT(!type.empty(), "Type is empty.");
2196      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2197                   "Multiple reading of section.");
2198      _sections.insert(std::make_pair(type,
2199        new _reader_bits::LineSection<Functor>(functor)));
2200      return *this;
2201    }
2202
2203
2204    /// \brief Add a section processor with stream oriented reading
2205    ///
2206    /// The first parameter is the type of the section, the second is
2207    /// a functor, which takes an \c std::istream& and an \c int&
2208    /// parameter, the latter regard to the line number of stream. The
2209    /// functor can read the input while the section go on, and the
2210    /// line number should be modified accordingly.
2211    template <typename Functor>
2212    SectionReader& sectionStream(const std::string& type, Functor functor) {
2213      LEMON_ASSERT(!type.empty(), "Type is empty.");
2214      LEMON_ASSERT(_sections.find(type) == _sections.end(),
2215                   "Multiple reading of section.");
2216      _sections.insert(std::make_pair(type,
2217         new _reader_bits::StreamSection<Functor>(functor)));
2218      return *this;
2219    }
2220
2221    /// @}
2222
2223  private:
2224
2225    bool readLine() {
2226      std::string str;
2227      while(++line_num, std::getline(*_is, str)) {
2228        line.clear(); line.str(str);
2229        char c;
2230        if (line >> std::ws >> c && c != '#') {
2231          line.putback(c);
2232          return true;
2233        }
2234      }
2235      return false;
2236    }
2237
2238    bool readSuccess() {
2239      return static_cast<bool>(*_is);
2240    }
2241
2242    void skipSection() {
2243      char c;
2244      while (readSuccess() && line >> c && c != '@') {
2245        readLine();
2246      }
2247      line.putback(c);
2248    }
2249
2250  public:
2251
2252
2253    /// \name Execution of the reader
2254    /// @{
2255
2256    /// \brief Start the batch processing
2257    ///
2258    /// This function starts the batch processing.
2259    void run() {
2260
2261      LEMON_ASSERT(_is != 0, "This reader assigned to an other reader");
2262
2263      std::set<std::string> extra_sections;
2264
2265      line_num = 0;
2266      readLine();
2267      skipSection();
2268
2269      while (readSuccess()) {
2270        try {
2271          char c;
2272          std::string section, caption;
2273          line >> c;
2274          _reader_bits::readToken(line, section);
2275          _reader_bits::readToken(line, caption);
2276
2277          if (line >> c)
2278            throw FormatError("Extra character at the end of line");
2279
2280          if (extra_sections.find(section) != extra_sections.end()) {
2281            std::ostringstream msg;
2282            msg << "Multiple occurence of section: " << section;
2283            throw FormatError(msg.str());
2284          }
2285          Sections::iterator it = _sections.find(section);
2286          if (it != _sections.end()) {
2287            extra_sections.insert(section);
2288            it->second->process(*_is, line_num);
2289          }
2290          readLine();
2291          skipSection();
2292        } catch (FormatError& error) {
2293          error.line(line_num);
2294          error.file(_filename);
2295          throw;
2296        }
2297      }
2298      for (Sections::iterator it = _sections.begin();
2299           it != _sections.end(); ++it) {
2300        if (extra_sections.find(it->first) == extra_sections.end()) {
2301          std::ostringstream os;
2302          os << "Cannot find section: " << it->first;
2303          throw FormatError(os.str());
2304        }
2305      }
2306    }
2307
2308    /// @}
2309
2310  };
2311
2312  /// \brief Return a \ref SectionReader class
2313  ///
2314  /// This function just returns a \ref SectionReader class.
2315  /// \relates SectionReader
2316  inline SectionReader sectionReader(std::istream& is) {
2317    SectionReader tmp(is);
2318    return tmp;
2319  }
2320
2321  /// \brief Return a \ref SectionReader class
2322  ///
2323  /// This function just returns a \ref SectionReader class.
2324  /// \relates SectionReader
2325  inline SectionReader sectionReader(const std::string& fn) {
2326    SectionReader tmp(fn);
2327    return tmp;
2328  }
2329
2330  /// \brief Return a \ref SectionReader class
2331  ///
2332  /// This function just returns a \ref SectionReader class.
2333  /// \relates SectionReader
2334  inline SectionReader sectionReader(const char* fn) {
2335    SectionReader tmp(fn);
2336    return tmp;
2337  }
2338
2339  /// \ingroup lemon_io
2340  ///
2341  /// \brief Reader for the contents of the \ref lgf-format "LGF" file
2342  ///
2343  /// This class can be used to read the sections, the map names and
2344  /// the attributes from a file. Usually, the LEMON programs know
2345  /// that, which type of graph, which maps and which attributes
2346  /// should be read from a file, but in general tools (like glemon)
2347  /// the contents of an LGF file should be guessed somehow. This class
2348  /// reads the graph and stores the appropriate information for
2349  /// reading the graph.
2350  ///
2351  ///\code
2352  /// LgfContents contents("graph.lgf");
2353  /// contents.run();
2354  ///
2355  /// // Does it contain any node section and arc section?
2356  /// if (contents.nodeSectionNum() == 0 || contents.arcSectionNum()) {
2357  ///   std::cerr << "Failure, cannot find graph." << std::endl;
2358  ///   return -1;
2359  /// }
2360  /// std::cout << "The name of the default node section: "
2361  ///           << contents.nodeSection(0) << std::endl;
2362  /// std::cout << "The number of the arc maps: "
2363  ///           << contents.arcMaps(0).size() << std::endl;
2364  /// std::cout << "The name of second arc map: "
2365  ///           << contents.arcMaps(0)[1] << std::endl;
2366  ///\endcode
2367  class LgfContents {
2368  private:
2369
2370    std::istream* _is;
2371    bool local_is;
2372
2373    std::vector<std::string> _node_sections;
2374    std::vector<std::string> _edge_sections;
2375    std::vector<std::string> _attribute_sections;
2376    std::vector<std::string> _extra_sections;
2377
2378    std::vector<bool> _arc_sections;
2379
2380    std::vector<std::vector<std::string> > _node_maps;
2381    std::vector<std::vector<std::string> > _edge_maps;
2382
2383    std::vector<std::vector<std::string> > _attributes;
2384
2385
2386    int line_num;
2387    std::istringstream line;
2388
2389  public:
2390
2391    /// \brief Constructor
2392    ///
2393    /// Construct an \e LGF contents reader, which reads from the given
2394    /// input stream.
2395    LgfContents(std::istream& is)
2396      : _is(&is), local_is(false) {}
2397
2398    /// \brief Constructor
2399    ///
2400    /// Construct an \e LGF contents reader, which reads from the given
2401    /// file.
2402    LgfContents(const std::string& fn)
2403      : _is(new std::ifstream(fn.c_str())), local_is(true) {
2404      if (!(*_is)) {
2405        delete _is;
2406        throw IoError("Cannot open file", fn);
2407      }
2408    }
2409
2410    /// \brief Constructor
2411    ///
2412    /// Construct an \e LGF contents reader, which reads from the given
2413    /// file.
2414    LgfContents(const char* fn)
2415      : _is(new std::ifstream(fn)), local_is(true) {
2416      if (!(*_is)) {
2417        delete _is;
2418        throw IoError("Cannot open file", fn);
2419      }
2420    }
2421
2422    /// \brief Destructor
2423    ~LgfContents() {
2424      if (local_is) delete _is;
2425    }
2426
2427  private:
2428
2429    LgfContents(const LgfContents&);
2430    LgfContents& operator=(const LgfContents&);
2431
2432  public:
2433
2434
2435    /// \name Node sections
2436    /// @{
2437
2438    /// \brief Gives back the number of node sections in the file.
2439    ///
2440    /// Gives back the number of node sections in the file.
2441    int nodeSectionNum() const {
2442      return _node_sections.size();
2443    }
2444
2445    /// \brief Returns the node section name at the given position.
2446    ///
2447    /// Returns the node section name at the given position.
2448    const std::string& nodeSection(int i) const {
2449      return _node_sections[i];
2450    }
2451
2452    /// \brief Gives back the node maps for the given section.
2453    ///
2454    /// Gives back the node maps for the given section.
2455    const std::vector<std::string>& nodeMapNames(int i) const {
2456      return _node_maps[i];
2457    }
2458
2459    /// @}
2460
2461    /// \name Arc/Edge sections
2462    /// @{
2463
2464    /// \brief Gives back the number of arc/edge sections in the file.
2465    ///
2466    /// Gives back the number of arc/edge sections in the file.
2467    /// \note It is synonym of \c edgeSectionNum().
2468    int arcSectionNum() const {
2469      return _edge_sections.size();
2470    }
2471
2472    /// \brief Returns the arc/edge section name at the given position.
2473    ///
2474    /// Returns the arc/edge section name at the given position.
2475    /// \note It is synonym of \c edgeSection().
2476    const std::string& arcSection(int i) const {
2477      return _edge_sections[i];
2478    }
2479
2480    /// \brief Gives back the arc/edge maps for the given section.
2481    ///
2482    /// Gives back the arc/edge maps for the given section.
2483    /// \note It is synonym of \c edgeMapNames().
2484    const std::vector<std::string>& arcMapNames(int i) const {
2485      return _edge_maps[i];
2486    }
2487
2488    /// @}
2489
2490    /// \name Synonyms
2491    /// @{
2492
2493    /// \brief Gives back the number of arc/edge sections in the file.
2494    ///
2495    /// Gives back the number of arc/edge sections in the file.
2496    /// \note It is synonym of \c arcSectionNum().
2497    int edgeSectionNum() const {
2498      return _edge_sections.size();
2499    }
2500
2501    /// \brief Returns the section name at the given position.
2502    ///
2503    /// Returns the section name at the given position.
2504    /// \note It is synonym of \c arcSection().
2505    const std::string& edgeSection(int i) const {
2506      return _edge_sections[i];
2507    }
2508
2509    /// \brief Gives back the edge maps for the given section.
2510    ///
2511    /// Gives back the edge maps for the given section.
2512    /// \note It is synonym of \c arcMapNames().
2513    const std::vector<std::string>& edgeMapNames(int i) const {
2514      return _edge_maps[i];
2515    }
2516
2517    /// @}
2518
2519    /// \name Attribute sections
2520    /// @{
2521
2522    /// \brief Gives back the number of attribute sections in the file.
2523    ///
2524    /// Gives back the number of attribute sections in the file.
2525    int attributeSectionNum() const {
2526      return _attribute_sections.size();
2527    }
2528
2529    /// \brief Returns the attribute section name at the given position.
2530    ///
2531    /// Returns the attribute section name at the given position.
2532    const std::string& attributeSectionNames(int i) const {
2533      return _attribute_sections[i];
2534    }
2535
2536    /// \brief Gives back the attributes for the given section.
2537    ///
2538    /// Gives back the attributes for the given section.
2539    const std::vector<std::string>& attributes(int i) const {
2540      return _attributes[i];
2541    }
2542
2543    /// @}
2544
2545    /// \name Extra sections
2546    /// @{
2547
2548    /// \brief Gives back the number of extra sections in the file.
2549    ///
2550    /// Gives back the number of extra sections in the file.
2551    int extraSectionNum() const {
2552      return _extra_sections.size();
2553    }
2554
2555    /// \brief Returns the extra section type at the given position.
2556    ///
2557    /// Returns the section type at the given position.
2558    const std::string& extraSection(int i) const {
2559      return _extra_sections[i];
2560    }
2561
2562    /// @}
2563
2564  private:
2565
2566    bool readLine() {
2567      std::string str;
2568      while(++line_num, std::getline(*_is, str)) {
2569        line.clear(); line.str(str);
2570        char c;
2571        if (line >> std::ws >> c && c != '#') {
2572          line.putback(c);
2573          return true;
2574        }
2575      }
2576      return false;
2577    }
2578
2579    bool readSuccess() {
2580      return static_cast<bool>(*_is);
2581    }
2582
2583    void skipSection() {
2584      char c;
2585      while (readSuccess() && line >> c && c != '@') {
2586        readLine();
2587      }
2588      line.putback(c);
2589    }
2590
2591    void readMaps(std::vector<std::string>& maps) {
2592      char c;
2593      if (!readLine() || !(line >> c) || c == '@') {
2594        if (readSuccess() && line) line.putback(c);
2595        return;
2596      }
2597      line.putback(c);
2598      std::string map;
2599      while (_reader_bits::readToken(line, map)) {
2600        maps.push_back(map);
2601      }
2602    }
2603
2604    void readAttributes(std::vector<std::string>& attrs) {
2605      readLine();
2606      char c;
2607      while (readSuccess() && line >> c && c != '@') {
2608        line.putback(c);
2609        std::string attr;
2610        _reader_bits::readToken(line, attr);
2611        attrs.push_back(attr);
2612        readLine();
2613      }
2614      line.putback(c);
2615    }
2616
2617  public:
2618
2619    /// \name Execution of the contents reader
2620    /// @{
2621
2622    /// \brief Starts the reading
2623    ///
2624    /// This function starts the reading.
2625    void run() {
2626
2627      readLine();
2628      skipSection();
2629
2630      while (readSuccess()) {
2631
2632        char c;
2633        line >> c;
2634
2635        std::string section, caption;
2636        _reader_bits::readToken(line, section);
2637        _reader_bits::readToken(line, caption);
2638
2639        if (section == "nodes") {
2640          _node_sections.push_back(caption);
2641          _node_maps.push_back(std::vector<std::string>());
2642          readMaps(_node_maps.back());
2643          readLine(); skipSection();
2644        } else if (section == "arcs" || section == "edges") {
2645          _edge_sections.push_back(caption);
2646          _arc_sections.push_back(section == "arcs");
2647          _edge_maps.push_back(std::vector<std::string>());
2648          readMaps(_edge_maps.back());
2649          readLine(); skipSection();
2650        } else if (section == "attributes") {
2651          _attribute_sections.push_back(caption);
2652          _attributes.push_back(std::vector<std::string>());
2653          readAttributes(_attributes.back());
2654        } else {
2655          _extra_sections.push_back(section);
2656          readLine(); skipSection();
2657        }
2658      }
2659    }
2660
2661    /// @}
2662
2663  };
2664}
2665
2666#endif
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